I'm just wondering is there a technology like this?Transforming a Ram into a file system which makes file manipulation and transfer easier.
A ram which can be partitioned. And which can temporarily store the files that needs constant transfer from the computer to an external device.

Actually you're probably talk about a disk cache more than a RAM disk, based on the sentence "which can temporarily store the files that needs constant transfer from the computer to an external device".

Windows already has files caching, which keeps in RAM the most needed files. A lot of improvements has been made in Vista and especially Windows 7 in that regards. This is called SuperFetch.

Microsoft also created ReadyBoost, which uses a USB key as temporary memory storage when RAM is limited.